A number of proven and alleged terrorist plots have emerged in the UK since the Twin Towers attacks in September 2001:

Dec 2001: Richard Reid, a British-born convert to Islam, tries to blow up an airliner, bound from Paris to Miami, with a shoe bomb. Reid is in prison in the US.

Saajid Badat, another Briton, is jailed for 13 years for plotting to become a shoe bomber, but pulled out.

Jan 2003: Anti-terrorist police find a poison factory in a flat in Wood Green, north London. Days later, a raid on a flat in Manchester ends in the murder of a Stephen Oake, a special branch officer.

March 2004: British-born extremists of Pakistani background are arrested in the “fertiliser plot” case. They have more than half a ton of ammonium nitrate fertiliser, a basic ingredient of home-made explosives, in a self-storage depot in Hanwell, west London.

July 2005: Four British men blow themselves up on three Tube trains and a bus in central London, killing 52 passengers.

Two of them - Mohammed Sidique Khan and Shehzad Tanweer - had trained as terrorists in Pakistan.

July 2007: A jury is deciding the fate of a number of men accused of trying to repeat the carnage of July 7, 2005 on July 21, 2005.

In a separate case, a number of people are accused of plotting to blow up jets.